Method of saturating sheet material



Sept. 23, 1930. G. P. HEPPES METHOD 0 F SATURATING- SHEET MATERIAL FiledFeb. 5, 1921 2 Sheets-Sheet l S p 9 Q VG. P. HEPPES ,58

METHOD OF {SATURATING SHEET MATERIAL Filed Feb. 3, 1927 2 Sheets-Sheet 2r v 1 4 5 Q I Jywggexw.

4 I eagyej Patented Sept. 23 1930 UNIT-ED STATES PATENT OFFICE GEORGE P.HEPPES, OI CHICAGO HEIGHTS, ILLINOIS, ASSIGNOR, BY HESNE ASSIGN- MENTS,TO THE PATENT AND LICENSING CORPORATION, OF BOSTON, MASSACHU- SETTS, ACORPORATION OF MASSACHUSETTS METHOD OF SATURATING SHEET MATERIALApplication filed February a, 1927. Serial No. 165,558.

This invention relates to apparatus for saturating absorbent materialparticularly in sheet form and has for its objects not only to saturatethe material to a higher degree than has been possible with apparatusheretofore in use for that purpose, but also to control the saturationso as to produce definite degrees of saturation less than complete if sodesired. My invention finds a particular practical exemplification inthe problem of saturating sheets of felted fibrous stock commonly usedas a foundation or base for fabricated roofing. Such stock is commonlymade of rag or asbestos fibers or mixtures of these or other fibers, thesheets being formed on a paper-making machine so that the fibrousmaterial is interfelted into a bibulous structure capable of absorbing aconsiderable quantity of suitable saturants. In the manufacture ofroofing elements from raw felt, it is customary to saturate the feltwith a suitable waterproofing material so as to make the sheet waterrepellent. For this purpose, a low melting-point asphalt is customarilyused since asphalt of this kind can readily be.

heated to a relatively high degree of fluidity without raising thetemperature so high as to char or injure the fibrous material of thesheet when immersed in a bath of the molten saturant for a sufficienttime to effect approximately the maximum degree of saturation possiblefrom a single immersion of the sheet. It has been found that a sheet ofraw roofing felt when immersed in a bath of asphalt having a meltingpoint of from 120 to 150 F. heated to a temperature of approximately 300F.is quickly saturated to about 70 per cent. of its theoreticalcapacity, after which no more saturant enters the sheet, no matter howlong the sheet may be left in the bath. The saturation of roofing feltin the manufacture of roofing units according to general practice thusrarely reaches 80- per cent.

of the theoretical maximum. Feltwhich is saturated to that extent onlyis thus left with pores and voids capable of absorbing'some 20 per cent.of moisture. This constitutes an inherent weakness in the roofingelements made from the felt. which makes them subject to deteriorationby absorption of moisture traction of the asphalt in the pores and voids1 of the sheet together with whatever residual gases and vapors may beentrapped in such pores and voids, sucks some of the excess asphalt fromthe surfabe into the sheet so that a sheet thus saturated and cooled isfound to have absorbed saturant to very nearly 100 per cent. of itstheoretical capacity. I have found moreover that a saturation very closeto the theoretical maximum can be obtained by cooling the sheet with anexcess of saturant on one face only of the sheet. This is believed to bedue to the fact that the face from which the excess is substantiallyentirely removed when the sheet leaves the bath starts to coolimmediately, causing the asphalt in the pore spaces at the surface ofthe felt to become sluggish and thereby to prevent air from being suckedinto the sheet through that face. On the other hand, the surface onwhich an excess of hot asphalt is allowed to remain does not begin tocool at once since it is kept heated for a time by the presence of thelayer of excess asphalt on the face. The cooling therefore of theasphalt in the sheet proceeds from the uncoated face of the felt and asthe saturant and gases within the sheet contract, they suck in moreparticularly the excess from the coated face, suction of air from theuncoated face being practically prevented by the initial chilling ofasphalt in the superficial pore spaces thereof. In this manner,satisfactory results have been obtained in the saturation of roofingfelt by excess. being left on one face only of the felt as it emergesfrom the saturating bath.

It has been customary heretofore to run the sheet of roofing felt whichhas passed through the saturating bath to a cooling device comprising alooping mechanism which receives the saturated 'felt in festoons andfeeding the saturated sheet from the saturat-.

allows it'to cool by expdsure to the air. In

ing tank to the looper, it has heretofore been found necessary as apractical matter to remove excess saturant from the faces of the sheet.Unless this were done, difliculty has been experienced with traction ofthe feeding rolls, excess saturant on the sheet causing the sheet toslip on the rolls. A further ditficulty has arisen from the presence ofexcess saturant on'the' lower face of the sheet due to the fact thatsuch excess was liable to cause the sheet while cooling to stick to thelooper bars over which it was festooned so that upon attempted removalof the sheet, it was liable to tear. By my invention, I provide meansfor squeezing and feeding the sheet from the saturating bath to thelooper mechanism but leaving a sufiicient amount of excess saturantthereon without, however, losing traction. Moreover, the apparatusembodying my invention prevents the sticking of the saturated sheet tothe looper bars.

An. important feature of my invention is embodied in a special type ofsqueeze roll which engages the upper face of the sheet as it emergesfrom the saturating tank. This roll is provided with recesses ofdesired-number, size and shape formed on the face of the roll, theserecesses serving as temporary reservoirs to receive some of the excesssaturant on the face of-the sheetleaving the saturating tank and to.permit such saturantto pass the squeeze rolls and to remain on the faceof the sheet. during the subsequent cooling thereof. The amount ofexcess saturant remaining. on the face of the sheet. after passing therolls may be accurately controlled by the size and shape of the" holesand the spacing of the rolls. Various other advantageous features willbezapparent to one skilled in the art from the following description andon the drawings, of which,-

Figure 1 represents diagrammatically apparatus for carrying out some ofthe steps of manufacture of roofing, this apparatus Q containing anembodiment of my invention.

' Figure 2 illustrates another arrangement of apparatus containing anembodiment of my invention.

Figure 3 illustrates apparatus for use with a modified form of myinvention.

Figure 4 indicates a fragment of sheet showing the pattern of .excessasphalt lefton a face thereof by a roll'such as shownin Figure 5. rFigures 5, 6 and 7 are fragmentary perspectivesof rolls having recessedportions of various configurations.

Figure 8 shows a, roll with recesses of adjustable capacity.

Figure-9 is a fragmentary transverse section of a roll such as is'shownin Figure 8.

Figure 10 is a perspective of a serrated doctor used with the apparatusindicated in Figure 3.

Figures 11, 12 and 13 are fragmentary perspectives of looper bars havingprojections of various shapes thereon.

Referring to Figure 1, a roll of raw roofing felt is indicated at 20.This felt may be led by suitable guide rolls into'a saturating tank 21which is customarily provided with means for maintaining a pool ofsaturant therein at any; desired temperature. The sheet may be led overa series of rolls 22 in the tank to secure thorough contact with thesaturant and to permit bubbles of air and vapor issuing from the sheetto escape therefrom. The sheet upon leaving the bath of molten asphaltin the container 21 may be led directly to a pair of squeeze rolls 23,24, or if desired may have the excess saturant on its upper facedoctored therefrom as at 25, after which a secondary application ofwaterproofing material may be applied as by'a suitable spout 26. Thematerial supplied for the secondary coating may be similar to that inthe container 21 or preferably may be an asphalt having a higher meltingpoint such for example as is commonly used for coating the saturatedsheet. Of the pair of squeeze rolls 23, 24, which draw the saturatedsheet from the tank and feed it toward the looper mecha-. nism, thelower roll 23 is adapted to contact With the upper face of the sheet,the upper roll 24 being adapted to engage the lower face of the sheet,the sheet beingthreaded between these rolls in such a manner as totially all ofthe excess saturant thereon, the

recesses permitting substantial quantities of excess saturant to remainon the portions of the surface not touched by'the lands. In the normaloperation ofthe machine, a slight excess Will be left on the squeezedareas of the sheet, heavier excess being left on the remainlUU ingareas. These recesses may be of any desired number, area, depth orshape. As exemplified in the form of roll shown in Figure 5, therecesses comprise a series of longitudinal grooves intersected by aseries of peripheral grooves, these grooves being, by way of example,about one-quarter of an inch apart and having'a width and depth ofapproximately one-eighthof an inch. The number, size and distribution ofthe grooves, however, will depend upon the characteristics of. thesaturant and of thesheet as well as the degree. of saturation desired.By regulating the size, number and distribution of i are preferablysmaller than those in the. roll; 23, and if desired, the'roll 24 mayhavea the grooves in the face of the roll, the amount of'excess saturantleft thereon after the sheet has passed between the squeeze rolls may beaccurately controlled, this control being not subject to tampering withby operators of the machine. If the excess saturant left on the sheet islow melting-point asphalt such as is used in the saturating bath, it isdesirable that the amount of excess thereof left on the face of thesheet be carefully regulated, sincea deficiency would result in aninsuflicient saturation of the sheet while an excess would result in aninferior roofing element subject to slippage of the waterproofing coatof high. melting-point asphalt which is subsequently applied thereto,since an excess of low melting-point asphalt interposes a layer tooreadily affected by solar heat. Such readily affected layer of lowmelting-point asphalt remaining on a completely cooled sheet prevents acoating layer of high melting-point asphalt from direct engagement withand anchorage to the fibers of the foundation sheet. The rollillustrated in Figure leavesexcess saturant on the sheet in a checkeredpattern such as shown in Figure 4, these crisscross lines. of saturantquickly spreading to form a fairly uniform layer of asphalt which issucked into the sheet during the cooling thereof. Other forms ofrollsurfaces may be employed, however, as found desirable or convenient, afew of these being illustrated in Figures 6, 7 and 8. It is obvious,however, that-many other patterns may be'devised such for example asspiral grooves which may be arranged to lead from'the center line of theroll face toward the ends thereof, such a pattern having the additionalfunction of tending to keep the sheet prop erly stretched laterally. Inorder to facilitate adjustment of the capacity of a roll to pass excesssaturant, I may provide recesses of variable capacity, as shown inFigures 8 and 9, wherein the rec'esses are shown as cvlindrical in form,the bottoms being the heads of screws 27 which are threaded intosuitable holes 28 in the roll. Any pattern of recesses, however, whichprovides a satisfactory distribution of excess asphalt on the face ofthe sheet coming in contact with the roll comes within the purview of myinvention.

If desired, the upper roll 24 of the pair of squeeze rolls, which in theapparatus illustrated feed the sheet from the saturating tank, may alsobe provided with grooves in its face. This roll is adapted to contactthe under face of the sheet and for reasons hereinbefore set forth, itis considered advantageous in order to avoid certain practicaldifficulties in handling the sheet to remove most. if not all, of theexcess asphalt adhering to .the sheet 'as it leaves the saturating bath.For this reason, the grooves in the roll 24 plain ungrooved face.

from the face thereof. be heated in order to prolong the fluid condi- Itis understood, however, in case the sheet should be fed to apparatus inwhich, substantial excess saturant on the under face of the sheet would'not be objectionable, it is possible to leave any desired quantity ofexcess saturant on the under face as well as on the upper face. Theexcess asphalton the sheet after passing the rolls 23, 24 will ingeneral be sufliciently fluid to spread under the act-ion of gravity andsurface tension to form a fairly uniform layer on the sheet, thisspreading action being indicated in part in Figure 4. If desired,however, the spreading may be hastened by a spreader such as a steampipe 29 or bar 30 extending across the sheet and in light contacttherewith.- The spreader should preferably be heated to prolong thefluency of the excess asphalt, but this is 7 not necessary.

Another arrangement of squeeze rolls may be employed involving the useof a third roll (not shown) located beneath the roll 23..

With such a set of rolls, the upper and lower rolls being f'plain andthe middle roll being recessed, the sheet would receive two squeezes soas to remove more of the saturant from the lower face of the sheet whileleaving a measured amount of excess on the upper face,

In the looping mechanism as indicated in Figure 1, a pair of feed rolls31, 32 may' be I used to feed the sheet coming from the rolls 23, 24into the looping apparatus. The sheet,

after leaving the squeeze rolls 23, 24'will. according to my invention,have a predetermined or controlled excess of Waterproofing material onthe upper face thereof .and if desired a lesser excess on the lower facethereof. Some of this excess will normally be upon the upper face ofthesheet when it reaches the feed rolls 31, 32. In order to avoidsqueezingthis unabsorbed excess from the face of the sheet, I preferablyprovide the face of the roll 31 with grooves or other recesses which maybe similar 'to those in the roll 23 so that the sheet is carried throughthese feed rolls without loss of traction and also without removal ofthe excess coating The roll 31 may also tion of the excess saturant onthe upper face of the sheet. If substantial excess be lefton the underface of the sheet, the roll 32 should be suitably recessed to preventsqueezingsuch excess therefrom. The looping mechanism itself comprisesessentially an endless carrier 33 composed of a pair of. parallel chainssupporting by their ends a series of looper bars 34. The chains of thecarrier 33 pass over and are driven by suitable sprocket wheels as at35, the progress of the bars 34 being continuous and relatively slow.

The feed wheels 31, 32 feed the flexible saturated sheet into festoonsbetween successive looper bars 34. A suitable idle roll 36 is Theprogress of the looper bars 34 is so timed in relation to the speed ofthe feed rolls 31,

' 32 that when a sufficient length of .the sheet has been fed between apair of succssive looper bars to form a full festoon, the looper bar.comes in contact with the lower portion of the roll 36, the latter beingof sufficient weight to pinch the sheet between it and the looper barand thus to prevent any more of the sheet being fed into the festoonahead of 'such looper bar. This results in the beginning of the nextfestoon which immediately follows this looper bar and thus the loopingprocess is repeated. In order to prevent the squeezing of excess asphaltfrom the face of the sheet which overlies the looper bars, Imay alsosupply the roll 36 with recesses or [grooves to receive temporarily suchquantities of excess saturant as still remain on the upper surface ofthe sheet when the looper bar comes in contact'with the pinching 'rollInstead 'of-remo'ving substantially all excess saturant from the bottomof the sheet as it leaves the saturating bath, I may if desired providethe face of the feed'rolls 24 and 32 with grooves so as to permit thedevice generally indicated at 41' a protective coat of highmelting-point asretention of a substantial excess of saturant ontheunder face as well as upon the upper face of the sheet. In order toavoid the well known dificulty usually arising from excess saturant onthe under face of the sheet, namely, the liability of the sheet to stickto thelooper bars, I may provide the looper .bars with raised contactpoints (Figures form of stars,-knobs, or other spaced surfacesof smallarea to support the sheet and to hold the greater part of'the area ofthe lower face of the sheet out of contact with the looper bar.

The'ex osureof the sheet to the atmos-, phere in t e looper ispreferably of suflicient duration to cool the sheet to approximately themelting point of the saturant in the sheet and at thesame time to allowsubstantially complete absorption of the asphalt into the sheet,resulting from the sucking in of the excess asphalt left on one-or bothsurfaces of the sheet As hereinbefore set forth, it is preferable toregulate the amount of excess of low melting-point asphalt left i on theface or faces of'the' sheet by forming the recesses in the squeezerolls'of the proper size so that by the time the sheet is withdrawn fromthe looper, all of the excess on the faces thereof will have been drawninto the body of the sheet and will have become congealed withinthepores and voids thereof. Upon leaving the looper, the sheet may befed as by suitable feed rolls 39, 40 to a coating by which 11, 12 and13) which may be in the' the two tanks.

phalt is applied to the upper face of the sheet, this coatin being,preferably surfaced with' commmuted material such as crushed slate orits equivalent, this slate or grit being applied as by apparatusconventionally shown at 42 and rolled into intimate contact with thecoating as by press rolls 43. The excess of coatingumaterial which mayrun off the upper surface of the sheetmay be caught in a receptacle44from which also may be picked up coating asphalt to be applied in a thinlayer to the under side of the sheet as 'is customary in the roofingindustry.

In case the secondary application of asphalt by the spout 26 -(Figure 1)in the process of saturating the sheet is of high melting-point asphaltrather than the low melting-point variety, able receptacle 45 to catchanyexcess falling from the sheet,jthis'excess being transferred byanysuitable means to the receptacle 44 to supply additional asphalt for theunder coat of the sheet.

. l In Figure 2 is illustrated a modified form of saturating apparatuswith which'l may use my; improved 4 this apparatus comprises asaturating ,tank 21 adapted to hold a bath of molten low melting-pointasphalt. The usual rolls 22 are provided to guide the sheet through the.bath. Upon leaving the containeri21,'the sheet is preferably fedbetweena set of squeezing rolls 46, 47, '48 which emove' excess asphalt fromb'th faces of the sheet and also tend to work some of into the inmostp'ortionsof the sheet. The sheet may then e run directly to a secondtank 49 containing a secondary saturating bath, or'may first be cooledas b a looper conventionally indicated at 50, or *another suitablecooling means. After suitable 1mmersion in the secondary saturatingbath, the sheet may be then passed between squeeze rolls 23, 24, whichare preferably similar to those shown in Figure 1, either or both ofwhich may be recessed as hereinbefore described. From these rolls thesheet is taken to a looping apparatus similar to that shown in Figure 1,afterwhich the sheet is further operated on as desired. The use of aseparate tank 49 for saturating permits greater control in the nature ofthe saturants applied to the sheet. If desired, the tanks 21 and 49 maycontain the same kind of substance, in which case a connecting pipe 51may be used to facilitate circulation through I may, however, use ahighermelting-point asphalt in the tank 49 than in the tank 21 so that agreater amount of excess may be left upon the face of the sheet thanwould be practicable in the case of the low melting-point asphaltcommonly used as an initial saturant. If an excess of low melting-pointasphalt, beyond what can be I may provide a suit- \squeeze roll. Asshown the asphalt absorbed in the process of cooling the sheet, is lefton the face of the sheet, this unabsorbed excess prevents a properbonding of the subsequently applied coating of high meltmg-point asphaltwith the fibers of the foundation sheet, so that the coating on thesurface of the shingle, being ordinarily surfaced with a layer of slate,is liable to slip when warmed by If, however, the secondary saturatingstep is carried out with high melting-point asphalt, some of thisasphalt will be sucked into the sheet and will thus firmly anchor anyexcesswhich may be left upon the surface after the sheet has beencooled, this excess having a. sufficiently high me'lting-point toprevent slippage of the surfacing layers in hot weather.

In Figure 3 is illustrated another means for carrying out my invention.According to this form, the sheet is passed between the usual squeezerolls 23, 24 upon leaving the saturating tank, which removesubstantially all the excess saturant from the face of thesheet.Additional waterproofing material which may or may not be similar tothat in the tank sheet which comprises the steps of first satu-' 21 isapplied at once to the upper face of the sheet as by a spout 26. Thesheet then passes under a doctor having a notched or serrated edge asshown in Figure 10. A guide roll 53 may be placed Opposite to the doctorto support the sheet against the edge of the latter.

The quantity of asphalt left on the sheet to be absorbed may becontrolled by the number and size of the notches in the doctor 52. It isobvious that such a doctor may be used on the under side of the sheet inconjunction with suitable means for applying excess asphalt to thatside. I

Having thus described certain embodiments of my invention, it should beevident to those skilled in the art that various changes andmodifications might be made therein without departing from its spirit orscope as defined by the appended claims.

, I claim 1. The method of saturating an absorbent sheet, whichcomprises applying an excess of molten saturant to the sheet, squeezingthe sheet, applying excess molten saturant to the squeezed hot sheet,removing from the surface of the sheet all but a predetermined quantityof excess molten saturant substantially equal to the amount which thesheet can absorb .in cooling, cooling the hot saturated sheet tocontract the saturant therein and cause said measured excess of moltensaturant to be drawn into the sheet. r i

2. The method of 'sautrating an absorbent sheet, which comprisesimmersing the sheet in a bath of molten asphalt, removing substantiallyall excess asphalt from the surface of the sheet, applying to the hotsheet other 7 molten asphalt, removing from the surface of the sheet allexcess molten asphalt, except the sun of-a: summer day.

saturant equal to the amount which the sheet can absorb in cooling,cooling the hot saturated sheet to contract the saturant therein andcause the said pre etermined quantity of molten saturant to be drawninto the sheet and subsequently applying coating, asphalt to said sheet.1

3. The method of saturating an absorbent sheet, which comprises applvingan excess of saturant to the sheet, removing substantially all excesshot saturant from the surface of the sheet, applying to the hot sheetother molten saturant having different characteris tics from the firstsaturant, removing from spaced zones of the surface of the sheetsubstantially all excess saturant but leaving on the surface of thesheet a predetermined quantity of excess molten saturant substantiallyequal to the amount which the. sheet can absorb in cooling, cooling thehot saturated sheet to contract the saturant therein and cause the saidpredetermined excess of molten saturant to be drawn into the sheet andsubsequently.

applying coating asphalt to the sheet. I

a. The method of saturating an absorbent rating the sheet with moltenasphalt, applying to the hot saturated sheet additional molten asphalt,removing from the surface of the sheet all excess molten asphaltexcept'a predetermined quantity sub- 5. The method of saturating anabsorbent sheet which comprises the steps of first saturating the sheetwith molten asphalt, applying an additional quantity of molten asphaltto the thus saturated sheet while the s eet is hot, said'additionalamount being substantially equal to that which the sheet can absorb incooling, and cooling the hot saturated sheet to contract the saturanttherein and cause the said additional quantity of molten asphalt to bedrawn into the sheet.

6. The method'of saturating an absorbent sheet which comprises the stepsof saturating the sheet to substantially of its theoretical capacity andproviding an excess of molten saturant on the sheet, removing from asurface of the sheet excess molten saturant except fora predeterminedquantitysubstantially equal to theamount which the sheet can absorb incooling and cooling the hot saturated sheet to contract the saturanttherein and cause said measured excess molten saturant to be drawn intothe sheet.

7. The method of saturating an absorbent sheet which comprisesmaintaining the sheet in a heated condition durin the steps, in a contnuous operatlon, of mmerslng the sheetto saturate the same and cause thesaturant to penetrate substantially the entire thickness of theabsorbent sheet and providing an excess of molten saturant on the sheet,removing from the surface of the sheet excess molten saturant except fora redetermined quantity substantiall e ua to the amount which the sheetcan absor in cooling and cooling the saturated sheet to contract the hot.saturant therein and cause the said excess of molten saturantto bedrawn into the sheet.

8. The method of saturating an absorbent sheet which comprisesmaintaining the sheet in a heated condition during the ste s, in .acontinuous operation, of immersing t e sheet to saturate the same andcause'the saturant to penetrate substantially the entire thicknessthereof, and providing an excess of molten saturant face only of thesheet excess molten saturant execept for a redetermined quantitysubstantially equa to the amount which the sheet can absorb in coolingand cooling the saturated sheet to contract the hot saturant therein andcause the said measured excess of molten saturant to be drawn into thesheet. The method of saturating an absorbent sheet which comprisesmaintaining the sheet in a heated condition continuous o eration, ofimmersing the sheet to saturate't e same and cause the satu'rantto'penetrate substantially the entire thickness of the sheet andproviding an excess of molten saturant on the sheet, rcmovingbfrom thesurface of the sheet, without su stantially indenting the sheet, excessmolten saturant except a predetermined quantity. substantially e ual tothe amount which the sheet can a sorb in cooling, continuously passingthe hot saturated sheet, "with the through a,coo1ing measured excessthereon, zone in an unrolled' condition whereby to subject both surfacesof the sheet to cooling atmosphere to contract the hot saturant withinthe sheet and cause the said measured excess of molten saturant to bedrawn therein, continuousl advancing the thus substantially comp etelysaturated sheet to a coating zone and applfying coating material to thesurface thereo and in finally applying comminuted surfacing material tothe sheet as it advances from the coating zone.

In testimony whereof I have aflixed my signature. I

.' p GEORGE HEPPES.

on the sheet, removing from one during the steps, in a

